The present invention relates to a computer having a serial bus interface connectable to a serial bus such as IEEE1394, a network controller applicable to this computer, and a system and remove activating method using the computer and the network controller.
Recently, to improve the portability of notebook personal computers (to be preferred to as PCs hereinafter), the heights and weights of computer main bodies are being decreased. As the heights and weights thus decrease, conventional connectors are becoming unmountable. In particular, a port (100 BASE-TX;RJ45) for connecting with a LAN (Local Area Network) is in many cases mounted on an extension device called a port replicator or base dock, since this port is unnecessary in mobile environments. However, even in a case like this the main body of a notebook PC requires a docking connector for connecting with this extension device. Hence, this construction is still unsatisfactory to implement lower profiles and lighter weights.
Accordingly, a technique is recently beginning to be demanded by which a notebook PC is equipped with only a serial bus interface such as IEEE1394 and connected to a LAN via a serial bus connected to this serial bus interface. Even when a notebook PC is thus connected to a LAN via a serial bus, this notebook PC must be able to be remotely activated from the LAN. This is to allow the system manager to remotely activate PCs in the office at night to automatically perform maintenance, e.g., update software in these PCs, thereby reducing the TCO (Total Cost of Ownership).
This remote activation is usually implemented by a mechanism by which a server transmits a remote activation packet to a PC via a LAN and, upon receiving this packet, the internal LAN controller of the PC generates a wake up signal to an internal power managing mechanism of the PC. However, when a notebook PC is connected to a LAN via a serial bus, the LAN controller is provided in a bridge device for connecting the LAN to the serial bus extending from the notebook PC. Therefore, it is in practice difficult to directly transmit a wake up signal from the LAN controller to the power managing mechanism in the PC. Hence, the conventional remote activating method cannot remotely activate a notebook PC connected to a LAN via a serial bus.
Accordingly, it is an object of the present invention to provide a computer, a network controller, and a system and remote activating method using the computer and the network controller, by which the conventional remote activating method is improved to realize remote activation from the LAN even when a PC is connected to the LAN via a serial bus.
According to one aspect of the present invention, there is provided a computer comprising: a serial bus interface for communicating with another node on a serial bus; a power controller; and wake up signal transmitting means for transmitting, when the serial bus interface receives a Link-on packet for activating the serial bus interface via the serial bus, a wake up signal to the power controller in response to the Link-on packet, thereby returning the computer to an operation state.
In this computer, the serial bus interface may comprise first interface means having a physical layer function for exchanging an electrical signal via the serial bus, and second interface means having a link layer function for providing data transfer service between the first interface means and a higher transaction layer, and the wake up signal transmitting means may be connected to a signal line which outputs a Link-on signal from the first interface means to the second interface means when the first interface means receives the Link-on packet, and may transmit a wake up signal to the power controller in response to the Link-on signal.
In this computer, the wake up signal transmitting means may be provided in the serial bus interface.
In this computer, the serial bus may be an IEEE1394 bus.
According to another aspect of the present invention, there is provided a network controller for connecting a computer to a computer network, comprising: a first interface connectable to a serial bus interface of the computer via a serial bus; a second interface connectable to the computer network; means for mutually connecting the first and second interfaces to thereby connect the computer to the computer network via the serial bus; and packet converting means for converting, when a remote activation request packet addressed to the computer is received from the computer network, the received remote activation request packet into a Link-on packet which a root node on the serial bus uses to activate a serial bus interface of another node on the serial bus, and transmitting the Link-on packet to the computer via the serial bus, thereby remotely activating the computer from the computer network.
In this network controller, the remote activation request packet may be one of a magic packet using a predetermined bit pattern and a specific pattern packet using any of several predetermined specific bit patterns, the network controller may further comprise storage means for storing contents of the specific bit patterns used as the specific pattern packet, and detecting means for detecting whether the received remote activation request packet is the magic packet or a specific pattern packet matching one of the specific bit patterns stored in the storage means, and the packet converting means may convert the received remote activation request packet into the Link-on packet when the detecting means detects a match.
In this network controller, the Link-on packet may be a packet which only a root node on the serial bus may issue to another node on the serial bus, and the network controller may further comprise means for delaying participation of the network controller into a tree identification protocol such that the network controller is determined as a root node in tree identification on the serial bus.
In this network controller, the serial bus may be an IEEE1394 bus.
In this network controller, the computer network may be a LAN (Local Area Network).
According to still another aspect of the present invention, there is provided a computer system comprising: a computer having a serial bus interface for communicating with another node on a serial bus; and a network controller having a first interface connectable to the serial bus and a second interface connectable to a computer network, the network controller connecting the computer to the computer network via the serial bus, wherein the network controller comprises packet converting means for converting, when a remote activation request packet addressed to the computer is received from the computer network, the received remote activation request packet into a Link-on packet which a root node on the serial bus uses to activate a serial bus interface of another node on the serial bus, and transmitting the Link-on packet to the computer via the serial bus, and the computer comprises wake up control means for returning, when the serial bus interface of the computer receives a Link-on packet addressed to the computer, the computer to an operation state in response to the reception of the Link-on packet.
In this system, the serial bus may be an IEEE1394 bus.
In this system, the computer network may be a LAN (Local Area Network).
According to still another aspect of the present invention, there is provided a remote activating method of activating from a computer network a node having a serial bus interface for connecting with a serial bus, comprising the steps of: receiving a remote activation request packet addressed to a specific node on the serial bus from the computer network by using a network controller for connecting the specific node to the computer network; converting the received remote activation request packet into a Link-on packet which a root node on the serial bus uses to activate a serial bus interface of another node; and transmitting the converted Link-on packet from the network controller to the specific node via the serial bus, thereby remotely activating the specific node from the computer network.
In this method, the serial bus may be an IEEE1394 bus.
In this method, the computer network may be a LAN (Local Area Network).
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.